What the Anesthesiologist Should Know before the Operative Procedure
Anesthetic management is influenced by the extent of the resection, the degree of underlying hepatic dysfunction and the functional status of the patient.
1. What is the urgency of the surgery?
What is the risk of delay in order to obtain additional preoperative information?
The urgency of the procedure is dictated by the indication for the resection. The majority of hepatic resections are performed for the treatment of malignancy (either primary or metastatic). The potential benefit of delaying surgery must be balanced against the risk of further tumor enlargement or metastasis.
Emergent: Hepatic resection is rarely emergent. Current management of hepatic trauma is conducted with selective operative intervention. When indicated, operative intervention typically consists of laparotomy with packing to control hemorrhage. In the setting of trauma, if indicated, hepatic resection is typical conducted at a later date following stabilization of the patient.
Urgent: Most hepatic resection is conducted to treat malignancy. Although not strictly urgent, the decision to delay the procedure must be balanced against the risk of metastasis or further advancement of the disease to a nonresectable form.
Elective: Hepatic resection for living donation or for benign lesions is elective.
2. Preoperative evaluation
For most surgical indications, preoperative evaluation should be tailored to the planned extent of the resection, the need for intraoperative hepatic vascular exclusion (occlusion of hepatic artery, portal vein, infraheptic IVC and suprahepatic IVC to exclude the liver from systemic circulation) and the patient’s pre-existing comorbidities.
Medically unstable conditions warranting further evaluation include: myocardial infarction with active ischemia, unstable arrhythmias, stroke, transient ischemic attack (TIA), chronic obstructive pulmonary disease (COPD) exacerbation.
Delaying surgery may be indicated if: patient is medically unstable.
3. What are the implications of co-existing disease on perioperative care?
b. Cardiovascular system
Acute/unstable conditions: Acute cardiac ischemia must be stabilized and treated according to standard guidelines prior to hepatic resection. Following stabilization, cardiac function must be optimized prior to proceeding with hepatic surgery.
Baseline coronary artery disease or cardiac dysfunction – Goals of management: Ensure optimization of baseline cardiac status with history and physical, baseline EKG and review of pre-existing functional and structural cardiac studies. For patients undergoing extensive resection with significant risk of hemorrhage and an inadequate history of functional status, proceed with functional testing (such as exercise stress test or dobutamine stress echocardiography). For patients with history of congestive heart failure, valvular abnormality or evidence of right heart dysfunction, obtain an echocardiogram to evaluate valvular and ventricular function. Extensive hepatic resection with vascular occlusive maneuvers entails the risk of significant hemorrhage and hemodynamic instability. Adequate cardiopulmonary reserve is essential for survival
Perioperative risk reduction strategies
Preinduction arterial line. Intraoperative hemodynamic monitoring of central venous pressure (CVP). Transesophageal echocardiography (TEE) or pulmonary artery (PA) catheter for patients with compromised ventricular function or significant coronary disease.
The routine conduct of major hepatic resection involves the use of hypovolemia (low CVP anesthesia) to reduce the risk of hemorrhage along with vascular occlusion procedures with attendant reductions in cardiac output and systemic pressures. Under such conditions, a patient’s elevated heart rate is necessary to maintain adequate cardiac output. The inability of a patient to tolerate hemodynamic instability, tachycardia and hypovolemia precludes the safe conduct of major hepatic resection. Discussion should take place with the surgeon and the patient regarding consideration of alternative forms of therapy.
Increase oxygen supply:
FiO2 of 1.0; maintain hemoglobin to preserve oxygen carrying capacity
Reduce oxygen demand:
a. the need for heart rate elevation to maintain cardiac output in the setting of hypovolemia required for the conduct of major hepatic resection precludes the aggressive use of beta blockers. b. Preload: is decreased prior to and during resection to minimize hemorrhage. It may be further effected by hepatic vascular exclusion maneuvers. For patients who are highly preload-dependent, consideration should be given to preoperative treatment of the underlying cardiac problem or pursuit of alternate therapies to liver resection. c. Afterload: use vasopressors to maintain adequate coronary perfusion pressure.
Patients with cirrhosis or portal hypertension are at risk for hepatopulmonary syndrome characterized by hypoxia. Patients with reduced room air oxygen saturations may be evaluated with arterial blood gas analysis, pulmonary function testing and contrast echocardiography.
Severe COPD has been associated with increased morbidity and mortality in patients undergoing hepatic resection.
Perioperative evaluation: Clinical history, review of pulmonary function tests, medications and frequency of exacerbations. Repeat pulmonary function tests if change in status is present by history or physical examination.
Perioperative risk reduction strategies: If medically optimized, continue preoperative pulmonary medications. Intraoperatively, ensure adequate exhalation time to prevent air trapping. Postoperatively, consider epidural for pain management. In the postoperative period use incentive spirometry, nebulizer therapy and steroid administration as appropriate.
Reactive airway disease (Asthma):
Perioperative evaluation: Assess severity of the disease based on frequency of exacerbations, triggers, medications, use of steroid therapy, number of emergency room visits, hospital admissions and intubations.
Perioperative risk reduction strategies: Continue baseline medications perioperatively. Supplement with nebulizer or steroid therapy as needed.
Laboratory testing for baseline sodium, potassium, creatinine, BUN and hemoglobin.
Perioperative risk reduction strategies
Hypovolemia (low CVP) is maintained during resection to reduce hemorrhage. Avoid nephrotoxic agents. Maintain adequate hemoglobin. Following resection of the mass administer fluids to achieve euvolemia
The presence of underlying chronic liver disease affects the morbidity and mortality of hepatic resection. Most patients undergoing resection for metastatic colon cancer have otherwise normal hepatic parenchyma. Patient with normal liver parenchyma have been reported to tolerate resections of up to 80%. For patients with Child-Pugh A and mild to moderate cirrhosis resection up to 60%-70% may be tolerated. For patients with hepatocellular carcinoma (HCC) and more significant liver disease, consideration should be given to liver transplantation.
History and physical exam focusing on findings associated with hepatic dysfunction or failure (easy bruising, petechiae, encephalopathy, ascites). Laboratory testing for AST, ALT, total, direct and indirect bilirubin, serum albumin, platelets, INR, PT, and PTT. Ultrasound can be used to screen for portal hypertension.
Perioperative risk reduction strategies
Optimize coagulation status if necessary.
Acute issues: Acute alterations in neurologic function or changes in mental status need to be resolved prior to surgery.
Chronic disease: Ensure that chronic disease is appropriately medically managed and optimized prior to surgery.
h. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (eg. musculoskeletal in orthopedic procedures, hematologic in a cancer patient)
4. What are the patient's medications and how should they be managed in the perioperative period?
i. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?
j. What should be recommended with regard to continuation of medications taken chronically?
Patients should continue to take the medications required to optimize their chronic preexisting conditions. Consideration should be given to withholding anticoagulants and antiplatelet agents. Decision to withhold should be made following a discussion with the patient’s surgeon and the prescribing physician regarding the risks and benefits of anticoagulation during the procedure.
k. How To modify care for patients with known allergies –
For patients with known allergies, avoid exposure to allergen.
l. Latex allergy- If the patient has a sensitivity to latex (eg. rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.
For patients with known latex allergy, avoid latex-containing products.
m. Does the patient have any antibiotic allergies- – Common antibiotic allergies and alternative antibiotics]
n. Does the patient have a history of allergy to anesthesia?
Documented: Avoid all trigger agents such as succinylcholine and inhalational agents. Ensure that the machine is clean or appropriately flushed. Ensure MH cart is available.
5. What laboratory tests should be obtained and has everything been reviewed?
Serum electrolytes, complete blood count, serum albumin, coagulation panel, liver enzymes; chest x-ray; cardiac imaging and testing as indicated by the patient’s medical history.
Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?
Major hepatic resection is carried out under general endotracheal anesthesia. An epidural may be placed for postoperative pain management. Major hepatic resection can lead to postoperative coagulopathy, however epidural analgesia has been used safely and effectively. Normalization of coagulation parameters (INR, PT, PTT, and platelet count) should be verified prior to postoperative removal of the epidural catheter.
6. What is the author's preferred method of anesthesia technique and why?
Establish large-bore peripheral venous access. Insert low thoracic/high lumbar epidural for postoperative pain control. Utilize standard monitors along with arterial catheter and central venous cannula. If patient has underlying left ventricular dysfunction, consider the use of a pulmonary artery catheter. Unless contraindicated, carry out general endotracheal anesthesia with standard induction. Epidural catheter may be used for analgesia intraoperatively.
Judiciously administer fluids over the course of the resection targeting a CVP no greater than 5 mm Hg. Administer colloid boluses for urine output <0.5 mL/kg/h. Should total hepatic venous exclusion (THVE) be required, fluid load the patient to raise CVP prior to clamping. For nonmalignant and noninfectious hepatic pathology, consider the use of a red blood cell salvage device. Have a rapid transfuser available. The decision to extubate at the conclusion of the case should depend on the extent of resection, degree of blood loss, and patient’s condition.
What prophylactic antibiotics should be administered?
Cefoxitin 1-2 g IV. If patient has a beta-lactam allergy, administer metronidazole 500 mg IV and ciprofloxacin 400 mg IV. (SCIP guidelines 2007)
What do I need to know about the surgical technique to optimize my anesthetic care?
Temporary occlusion of the hepatic inflow vessels may be conducted by the surgeon to reduce blood loss during parenchymal resection. The Pringle maneuver consists of total inflow occlusion with clamping of the portal vein and hepatic artery. It results in an approximately 10% increase in mean arterial pressure with a 40% increase in systemic vascular resistance and a 10% decrease in cardiac index. Intermittent clamping of the portal triad is usually well-tolerated. For tumors which are near or involve the IVC, total hepatic vascular exclusion (THVE) may be performed. THVE involves clamping of the portal triad (Pringle maneuver) along with the supraheptic and infrahepatic IVC. THVE allows major hepatic vein or IVC reconstruction. THVE is associated with a significant reduction in venous return (40%-60%) and cardiac output. Adequate volume expansion prior to clamping along with vasopressor support during THVE is necessary for hemodynamic stability. If the patient is unable to tolerate THVE, veno-venous bypass can be established to allow the procedure to proceed.
What can I do intraoperatively to assist the surgeon and optimize patient care?
Maintenance of low CVP has been associated with reduced blood loss during hepatic resection. CVP should not be allowed to rise above 5 mm Hg. Invasive arterial monitoring and adequate central access for vasopressor support should be instituted to safely manage the patient’s hemodynamics. Once the resection is completed, fluids may be administered to re-establish euvolemia.
What are the most common intraoperative complications and how can they be avoided/treated?
Major liver resections may be associated with significant blood loss. The degree of blood loss is a function of the extent of resection and the presence of preexisting coagulopathy. Hemorrhage can be especially brisk and difficult to control if the IVC is injured. On average, healthy donor undergoing right hepatectomies have been reported to lose up to 900 mL of blood. Appropriate management consists of the establishment of adequate large bore peripheral access. Packed red blood cells should be typed and crossed and available for transfusion. A rapid transfusion device should be available for use. Blood loss can be reduced by maintaining a low CVP throughout the resection. For patients undergoing resection for non-malignant and non-infectious pathology, a red blood cell salvage device may be used to reduce the need for transfusion of banked blood.
Reduction in systemic pressure may come about from inadvertent compression of the IVC during dissection or intentional clamping during THVE. For planned THVE, volume expansion to a CVP of 14 mm Hg or greater should help to stabilize the patient’s hemodynamic state during clamping.
The large field of exposure necessary for major hepatic resection can give rise to significant hypothermia which can inhibit effective coagulation. Hypothermia can be avoided through the use of fluid warmers as well as under- and over-body forced air warmers.
a. Neurologic: *** Type Here.
b. If the patient is intubated, are there any special criteria for extubation?
There are no special criteria for extubation. The decision to extubate should be based on standard criteria.
c. Postoperative management
What analgesic modalities can I implement?
Epidural or patient-controlled intravenous analgesia (PCA). If an epidural is used, be sure to verify normal coagulation parameters prior to removal of the catheter. Patients who undergo major hepatic resections can develop transient coagulopathy and thrombocytopenia in the postoperative period.
What level bed acuity is appropriate?
The level of bed acuity is a function of the patient’s underlying comorbidities, the extent of resection and the patient’s status following resection. Determinations must be made on a case-by-case basis. Generally, otherwise healthy patients without cirrhosis who have had less than 50% of their hepatic mass resected without significant blood loss and with good hemostasis can be managed on a standard inpatient surgical floor following recovery in the post-anesthesia care unit. For patients who have undergone more significant resections or who have had significant blood loss or issues with hemostasis, an intensely monitored setting is more appropriate for postoperative management.
What are common postoperative complications, and ways to prevent and treat them?
Postoperative complications include symptomatic pleural effusion; perihepatic abscess; hepatic insufficiency; urinary tract infection; pneumonia; renal insufficiency; hemorrhage requiring re-exploration; coagulopathy and wound infection.
What's the Evidence?
RedaiI, EJ, Brentjens, T. “Anesthetic considerations during liver surgery”. Surg Clin N Am. vol. 84. 2004. pp. 401-11. (Provides a concise overview of anesthetic management considerations for hepatic surgery.)
Celinski, SA, Gamblin, TC. “Hepatic resection nomenclature and techniques”. Surg Clin N Am. vol. 90. 2010. pp. 737-48. (Provides a concise overview of surgical management of hepatic resection.)
Alkozai, EM, Lisman, T, Porte, RJ. “Bleeding in liver surgery: Prevention and treatment”. Clin Liver Dis. vol. 13. 2009. pp. 145-54. (Provides an overview of the management of hemorrhage during liver resection.)
Shontz, R, Karuparthy, V, Temple, R. “Prevalence and risk factors predisposing to coagulopathy in patients receiving epidural analgesia for hepatic surgery”. Reg Anesth Pain Med. vol. 34. 2009. pp. 308-11. (Reviews data regarding the risk of coagulopathy associated with liver resection.)
Dixon, E, Vollmer, CM, Bathe, OF. “Vascular occlusion to decrease blood loss during hepatic resection”. Am J Surg. vol. 190. 2005. pp. 75-86. (Reviews evidence to support the use of vascular occlusion techniques to decrease blood loss during hepatic resection.)
Lau, WY, Lai, EC, Lau, SH. “Methods of vascular control technique during liver resection: a comprehensive review”. Hepatobiliary Pancreat Dis Int. vol. 9. 2010. pp. 473-81. (Reviews the use of vascular occlusion techniques to reduce blood loss during hepatic resection.)
Kamiyama, T, Nakanishi, K, Yokoo, H. “Perioperative management of hepatic resection toward zero mortality and morbidity: Analysis of 793 consecutive cases in a single institution”. J Am Coll Surg. vol. 211. 2010. pp. 443-9. (Reviews the factors associated with morbidity and mortality during hepatic resection.)
Jarnagin, WR, Gonen, M, Fong, Y. “Improvement in perioperative outcome after hepatic resection: Analysis of 1,803 consecutive cases over the past decade”. Ann Surg. vol. 236. 2002. pp. 397-407. (Identifies factors that improve outcomes in hepatic resection.)
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- What the Anesthesiologist Should Know before the Operative Procedure
- 1. What is the urgency of the surgery?
- What is the risk of delay in order to obtain additional preoperative information?
- 2. Preoperative evaluation
- 3. What are the implications of co-existing disease on perioperative care?
- b. Cardiovascular system
- c. Pulmonary
- d. Renal:
- e. GI:
- f. Neurologic:
- g. Endocrine:
- h. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (eg. musculoskeletal in orthopedic procedures, hematologic in a cancer patient)
- 4. What are the patient's medications and how should they be managed in the perioperative period?
- i. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?
- j. What should be recommended with regard to continuation of medications taken chronically?
- k. How To modify care for patients with known allergies -
- l. Latex allergy- If the patient has a sensitivity to latex (eg. rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.
- m. Does the patient have any antibiotic allergies- - Common antibiotic allergies and alternative antibiotics]
- n. Does the patient have a history of allergy to anesthesia?
- 5. What laboratory tests should be obtained and has everything been reviewed?
- Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?
- 6. What is the author's preferred method of anesthesia technique and why?
- What prophylactic antibiotics should be administered?
- What do I need to know about the surgical technique to optimize my anesthetic care?
- What can I do intraoperatively to assist the surgeon and optimize patient care?
- What are the most common intraoperative complications and how can they be avoided/treated?
- a. Hemorrhage:
- b. Hypotension:
- c. Hypothermia:
- a. Neurologic: *** Type Here.
- b. If the patient is intubated, are there any special criteria for extubation?
- c. Postoperative management